A forum for owners of Yamaha TTR250 trail and enduro bikes!

dan-reeves · Veteran Member

Sprockets (13-44?)

pedrosan · Senior Member

Hi Dan,

Are you in 5th or 6th when you're flat out? I have a Raid that was on 14/48 and have just swapped to 13/48. I haven't checked yet, but I suspect the top speed will be higher as when I was flat out with 14/48 the engine didn't have the power to pull 6th gear.

As I work it out, your gearing is higher than 14:48, so I would guess that swapping to 13/48 would let your engine pull 6th better and go faster.

Regardless, off road the lower gearing I now have is absolutely brilliant, a really good change.

I got my front and rear sprockets and renthal 520 o ring chain as a set from Brian at Totally TTRs (click here). I also got some other goodies. Really happy with it all.

Pete

dan-reeves · Veteran Member

Hi
I am in 5th gear as six doesn't seem to pull at all.
That doesn't seem a to bad, i will see what other people are running as well before making a decision.
Yeah i have bought from there it is brilliant, will get them all from there then :)
Thanks
Dan

LRJ · Senior Member

You have my sympathy regarding the rounded sump plug, Dan. I discovered the same thing right after I bought mine. A friend suggested that a pipe wrench would probably be effective at getting the old plug off, and he was right!

dan-reeves · Veteran Member

Yes was a bit of a pain!!
Ordering a new plug tonight, have got some snap on bolt extractors at work so hopefully these will get it out....
Dan

SHarper · Member

When I first got my TTR it needed a chain and sprockets, I went to the local bike shop and just asked for c & s for a TTR. In my eagreness to get out on it I didn't pay much attention, fitted them and had a lovely winter tootling about around the Peaks; it never pulled top gear, but I wasn't particularly bothered, it got up all the hills I pointed it at...

A good few months later, when I had to replace the wheel bearings, I thought that while the bike was apart I'd play with the gearing. It turns out that I was running a 14 tooth front and a 43 tooth rear!

Anyhoo, I've fitted a 46 tooth rear and a 13 tooth front, the chain is only just long enough, any shorter the rear tyre would be rubbing the swing arm, but by 'eck it's transformed the bike! It now pulls sixth gear and climbs hills in second that previously required first...

TTRfan · Super Guru

The correct gearing is incredibly important but its impossible to suggest a ratio that suits everyone as it entirely depends on what use is made of the bike and, if "green laned", how nadgery the lanes are.

Sounds like you have a good compromise for your type of riding biggrin

I was surprised to find out from an email exchange with a customer that he was running 15/40 confuse

But, he is using his TTR on tarmac only. He is getting an excellent mpg and top speed. My thoughts are that, to pull such high gearing, he must have a stonkingly good engine! He has promised to feed back with longer term mpgs etc after he has run this combination for a while.

I am still running 13/48 on my 325 and am happy with an easy 70mph top speed - not sure exactly how fast it will go if I just held the throttle pinned but am more than happy with 70mph on knobblies!

I have a good s/h 14 tooth front sprocket so should really fit that whilst the weather is not so good down here in Devon.

Brian

Haggis Hunter · Veteran Member

Hi Chaps, new boy here. Just thought I would add to this. Divide the number of rear teeth by the number of front teeth and this will give you your ratio i.e 44/14 = 3.14:1. Going larger on the rear and smaller on the rear will lower the ratio i.e 52/13 = 4.0:1. I am currently using a 13/48 setup which is good for my daily commute, a round trip of about 7 miles over steep rocky terrain. However the front sprocket wears quickly so next time I replace them (Which is about twice a year due to the sand that comes with the rocks!) I will go for a 14/52 which will give me a ratio of 3.71:1 compared to 3:69:1 on the existing setup, so my gearing will be slightly lower, which is good for me. I hope that the wear on the chain and front sprocket will be reduced due to the larger diameter. Top speed is not a worry for me as I can only get into 4th in one place, don't want to go any quicker, too many big rocks to make contact with and the track I follow is only about 1m wide and runs along a cliff top! (you really don't want to fall off here)

Hope I am not offending anyone, teaching to suck eggs etc by going into this in detail and I hope it helps those that are wondering what changing the number of teeth on the sprockets do to the gearing.

Peter.

KNjonjo · Veteran Member

My TTR had 13/44 sprockets and would easily do 110 km/h on tarmac in 6th gear. When off roading however, some rocky uphill sections required 1st gear and some clutch to keep the revs up.

My front sprocket was hooked so ordered a chain & sprocket set from Totally TTRs. My research on the forum found many riders saying 13/50 was excellent off road. I decided to try 13/48 since do quite a bit of tarmac riding and I didn't want to loose too much top speed.

With the new combo I can still hit 110 km/h but the engine revs are much higher than before so I find myself settling at 100 km/h.

The acceleration is so much better though so I think I'll stick with this gearing. I'm off for my first offroad ride tomorrow so I'll see how well it performs.

Phred · Veteran Member

I went out on a limb and tried 15/44 which has been a hit. I ride sand, highway, dirt, fire trail, and commute. What I found was that i could get more out of 1st and 2nd without ringing the neck out of the topend for sand. With trails and dirt, I found I could cruise and get punchy speed out of 3rd and fourth. On the highway i was unable to get 6th gear on an uphill, but level ground saw good speeds up to 140 in 6th without hitting topend. 5th gear also came up nicely covering the 80-110 range very well with plenty of power. I should also say that I combined all of this with a good exhaust and air intake mods, so the bike wasnt fighting intake/exhaust as well as tall gears. Its working for me!

BM Steve · Guru

Haggis Hunter wrote:
I will go for a 14/52 which will give me a ratio of 3.71:1

Hey Haggis Hunter, welcome to the forum, I have just recently fitted the 14/52 combo and they work well for me, allowing easy climbing of rocky hills instead of having to rely on momentum, I thought the same thing, reduced wear on the front sprocket and chain
Cheers
Steve

Cubber · Super Guru

I fitted 14:52 on my TTR in January of this year. biggrin

CHAIN & SPROCKET THREAD

I haven't had a bit of bother with the set up and I'm wholly satisfied. wink

It performs very well in the Devon lanes and will chug along happily in second gear in most situations - only resorting to first gear in tricky bits.
On the tarmac she will run all day at 65mph with no worries.

Martyn

KNjonjo · Veteran Member

My first offroad ride with my new sprocket combo (13/48 from 13/44) was very good. The bike pulls so much better and I didn't have to shift into 1st as often.

On tarmack between trails, I'm still able to comfortably hit 100 km/h.

As Brian said, the ideal combination will vary from rider to rider based on the type of riding one does. For me, this is the ideal combination.

pedrosan · Senior Member

Dan: did you get your sump plug out in the end? If so, how? Mine is stuck despite pipe wrench, heat, molegrips etc

TTRfan · Super Guru

pedrosan wrote:
Dan: did you get your sump plug out in the end? If so, how? Mine is stuck despite pipe wrench, heat, molegrips etc

Lay your TTR on its side and use a hammer and chisel (carefully!) on the edge of what's left of the sump plug to undo it. You might take a few chunks out of the nut before it moves but this technique has never failed for me!

As a last resort you may need to get a bar or another nut mig welded on to help release it.

Brian

pedrosan · Senior Member

I have been reluctant to do that so far but will try it today. I'll let you know... Eek!

Haggis Hunter · Veteran Member

Had the same problem on my raid when I first went to change the oil and found that the rather small bolt head rounded off. So it was out with the welder and nut was welded on and the plug came out no problem. Didn't want to put the old one back in so I had a hunt around and found that the sump plug from my sons dead CG125 field bike fitted. The plus point is it's 17mmA/F. No problems removing the plug now. Oh, and I always use a 6 point sockets where I can.

TTRfan · Super Guru

pedrosan wrote:
I have been reluctant to do that so far but will try it today. I'll let you know... Eek!

How did it go Pete?

dan-reeves · Veteran Member

Pete i haven't done mine yet :(
Will try and get around to it soon!
I will be using snap on bolt extracters that you hit over the head and as you undo it firmly grips, hopefully this is enough to get it moving!!

Dan

pedrosan · Senior Member

No joy. Wife has appropriated (stolen) the laptop and the desktop finally gave up its steam powered ghost, so can't put pics up at the mo. Laid it in its side, with tank off (what a difference!) and bashed away at a notch on the collar of the bolt to no joy. Will have to go down the welding route I think. I'm not riding it at the minute as I can't change the oil and its about worn out. Frustrating!

TTRfan · Super Guru

pedrosan wrote:
No joy. Wife has appropriated (stolen) the laptop and the desktop finally gave up its steam powered ghost, so can't put pics up at the mo. Laid it in its side, with tank off (what a difference!) and bashed away at a notch on the collar of the bolt to no joy. Will have to go down the welding route I think. I'm not riding it at the minute as I can't change the oil and its about worn out. Frustrating!

Bad luck on both the TTR and the IT front